Air cushion load-supporting devices

ABSTRACT

In an air cushion supported materials handling device of the type comprising a load-carrying platform carried by tubular support structure, part of which tubular structure also forms the handle for manual propulsion of the device, the platform has mounted on its underside a plurality of inflatable air pads, and the pressurized air is supplied to the inflatable air pads through the tubular support structure, and can be supplied also through the handle. Suitable control valves can be incorporated in the handle or in the tubular structure.

United States Patent {72] Inventor Clive A. F. Hawkins Yeovll, Somerset.England [21] Appl No 790,7[9 [22] Filed Jan. [3, I969 [45] Patented July20, 1971 [7 3] Assignce British Hovercraft Corporation Limited Yeovil,Somerset. England 32 Priority Nov. ll, 1968 [33] Great Britain |3l55452/68 [54] AIR CUSHION LOAD-SUPPORTING DEVICES 1 Claim, 7 DrawingPip.

[52] U.S.Cl l80/l2l, 180/1 16, ISO/I24, ISO/I25 5| lnt.Cl 560v 1/00,860v Hill [50] FieldofSearch l80/l24, 125, 1 l6, I21

[56] References Cited UNITED STATES PATENTS 3,276,530 10/1966 BomemanISO/124 3,493,071 2/1970 Street et a1. 180/124 3,082.836 3/1963 Billman180/124 3,161,247 12/1964 Mackie H 180/124 3,247,921 4/1966Latimer-Needham et al 180/124 3,392,800 7/1968 Swamy ISO/I25 3,466,0109/1969 lung 180/125 X FOREIGN PATENTS 782,892 4/1968 Canada 180/[25Primary Examiner-A. Harry Levy AtI0rneyLars0n, Taylor 8:. HindsABSTRACT: In an air cushion supported materials handling device of thetype comprising a load-carrying platform carried by tubular supportstructure, part of which tubular structure also forms the handle formanual propulsion of the device, the platform has mounted on itsunderside a plurality of inflatable air pads, and the pressurized air issupplied to the inflatable air pads through the tubular supportstructure, and can be supplied also through the handle, Suitable controlvalves can be incorporated in the handle or in the tubular structure.

PATENTEB JULZO :911 3593817 sum 1 OF 4 AIR CUSHION LOAD-SUPPORTINGDEVICES This invention relates to devices for the movement of loadsacross a surface and utilizes pressurized air for support, beingreferred to as air cushion vehicles.

It is the object of the invention to provide an uncomplicated and robustload-moving device having very low frictional resistance to movement.

in accordance with the present invention, I provide an air cushionvehicle comprising a load bearing structure having on its undersurfaceone or more flexible inflatable elements each defining within itsperiphery a region which is closed at its upper part, bounded across itssides by the element and open at its lower part, and means for conveyinga pressurized gaseous fluid to each region to form a cushion of fluidtherein to support the vehicle above the surface across which it is tooperate. The structure is formed partially by a tubular frameworkthrough which pressurized air is passed to form the cushion. it is to beunderstood by the term "elements" that these may be of any form where achamber is provided that can have gaseous fluid introduced into it, andwhere at least part of the walls of the chamber can be distended.

The invention now will be described by way of example with reference tothe accompanying drawings, wherein:

FIG. 1 shows the underside of a known vehicle having four flexibleinflflable elements, this being included only for purposes ofexplanation,

FIG. 3 diagrammatically illustrates a ducting and control valvearrangement that utilizes the handle and framework of a vehicle inaccordance with one form of the invention,

FIGS. 4 and 5 illustrate alternative duct arrangements where the controlvalve is associated with the handle of the vehicle,

FIG. 6 shows a multiple duct and control valve arrangement for selectivecontrol of delivery of the air at a plurality of positions, and

FIG. 7 shows a fragmentary view of the framework of a vehicle thatincludes a ducting and valve arrangement and attachment for a separablehandle. A load-bearing structure in the fonn of a rigid platform 10 hasa plurality of separate flexible inflatable elements ll spacedsymmetrically beneath it and sealed to it. The elements 11 are tubular,and for convenience are illustrated as being circular but can be of anysuitable tubular shape and form. An air duct system 12 is secured to theunderside of the platform 10, having a main duct l3 which providesconnection with a source of pressurized air and branch ducts 14 whichconnect with the inlet of each inflatable element 11. The elements IIhave at least one outlet port 15 that opens into the region 16 boundedby the element. The total area of the outlet port or ports 15 in eachelement is less than the area of the inlet orifice 17. Each branch duct14 can include an aspirator or injector 18.

In operation, a hose or airline from a pressurized air source, such as afactory compressed air system or separate air compressor, is connectedto the main duct l3 whereby air is supplied through the branch ducts 14to the interior of each flexible element ll which inflates and forms theregion 16 into a plenum chamber. Air discharges into the plenum chambersfrom the flexible elements It by way of the outlet ports 15 and formspressurized cushions of air capable of lifting the structure l0 and itsload off the surface upon which it rests. The pressurized air suppliedthrough the branch ducts 14 can, where necessary, entrain ambient air byway of the injectors 18, in order to provide improved mass flow of airto the cushion.

Referring now to FIG. 3, wherein the illustrated vehicle has an air ductsystem somewhat similar to that described above, but embodying one formof the present invention, the platform 31 comprises a tubular framework32 having a peripheral tube 33 and transverse tubes 34, with animpermeable panel or sheet 35 and inflatable elements 36 attachedbeneath. A tubular handle 37 is conduitly secured to the peripheral tube33 on a side where one end of the transverse tubes 34 are also secured.A hose connection 38 is fitted to the peripheral tube 33 near onejunction of the handle 37 with the peripheral tube 33. Two of thetransverse tubes 344 that cross above the inflatable elements 36 haveoutlet connections 39 thereto. COnduit communication is thereby providedbetween the hose connection 38 and the inflatable elements by way of thehandle 37 and the tubular framework 32. The ensure that communication isconfined to the most direct route plugs are positioned in the peripheraltube 33 at 40, 41, 42, and 43. A suitable manually operated valve, suchas a twist-grip type 44, is provided in the handle 37 for controllingflow of pressurized air to the inflatable elements 36.

Two further embodiments of the invention shown in FIGS. 4 and 5illustrate a simple means of construction incorporating strength withgreat utility. That shown in FIG. 4 comprises a single tubular frame 5|that is upturned at one end to form a handle 52, into which a l-shapedconnection 53 incorporating a flow control valve is fitted for theattachment of a compressed air hose 54. A rigid platform 55 is supportedbetween the level portions of the frame 51 and has four inflatableflexible elements 56 attached to its underside. The tubular frame 51provides the main ducting for distribution of the compressed air to theelements 56, which are each connected thereto by smaller bore tubes 57,572. The tubes 57 connect the two elements 56, that are nearer to thehandle 52, with conveniently positioned connections on the tubular frame51 at the side of the platform 55, whilst tubes 57a, connect the twoelements 56, that are remote from the handle 52, with connectionsprovided at the two ends of the tubular frame 51. Frame Sl can beconveniently closed to an endless configuration by joining the two endstogether with a coupling having two connections for tubes 57a.Regulation of the air supply is made by means of the valve in theconnection 53.

The embodiment shown in FIG. 5 is of similar general construction tothat of HO. 4, but instead of using the framework as a ducting fordistribution of compressed air to the inflatable flexible elements, thevalved connection 6! is a cruciform having only a straight-throughpassageway connecting with a tube 62 that extends centrally between twoof the flexible inflatable elements 63 beneath the platform 64, andterminates near the two elements 630 which are remotely disposed fromthe handle 65. A pair of smaller bore tubes 66a join elements 630 with aconnector provided at the end of tube 62, whilst another similar pair oftubes 66 connect elements 63 with tube 62 at a suitably adjacentposition.

Yet a further embodiment is illustrated in FIG. 6, wherein the tubularframework 7] of a platform 72 is adapted to allow separate control ofcompressed air to the interior of the flexible inflatable elements 73and to the plenum chamber 74 formed in each of the elements 73. Thisform of element 73 has no outlet orifice and is inflated similarly to aninner tube of a motor vehicle s tire; deflation being by way of a bleedvalve, referred to later. Elements 73 such as this provide buoyancy tovehicles where it is required, as, say, on canals and other waterways.

in this embodiment, the compressed air is conveyed by inlet tube 75 tothe center of handle 76, where it is directed into two flow paths, eachbeing outwardly through the handle 76 to the peripheral tube 77 andtransverse tubes 78 of the framework 71. One flow path, indicated bysolid arrows, is to the interior of elements 73 and the other flow path,indicated by hollow arrows, is to the plenum chambers 74. Plugs,suitably positioned in the framework 71 to maintain separation of theflow paths, are indicated at 79, and outlets to the interior of theelements 73 and plenum chambers 74 are indicated at 80 and 81respectively. Regulation of the compressed air delivered through the twoflow paths is achieved by means of manual flow control valves 82, 83,provided in han dle 76. Provided on the downstream side of the valve 82,which controls the airflow to the interior of the elements 73, is ableed valve 84 which permits deflation of the elements by venting theair from therein.

FIG. 7 shows a convenient arrangement of ducting, flow control valve andhandle attachment of the framework of a vehicle which has a removablehandle. The framework 91 is of tubular construction, and by theinclusion of suitable plugs 92 provides the main air ducting to theflexible inflatable elements (not shown). A compressed air inlet 93 anda conveniently positioned foot'operated flow control valve 94, disposeddownstream of the inlet 93, are provided on the peripheral tube 95 ofthe framework 9i, adjacent to a bracket 96 that provides a socket forone of the spade ends 97 of a handle 98.

Many modifications and alternative embodiments can be made within thescope of the claims as indicated by the following examples.

The flexible inflatable elements need not be of unitary construction,but may be formed from, say, two sheets of impermeable material of whichthe upper sheet is flat and the under sheet is folded or preformed intoa corrugation and the crest or crests thereof continuously sealed to theupper sheet, or alternatively the upper sheet may be substituted by theundersurface of the load supporting platform. Further, in a modificationof the flexible elements of the type illustrated in FIGS. 1 and 2, theymay have an impermeable membrane sealed across the top of each element,so as to form a plenum chamber in the element. Where a vehicle is movedby tug or tractor having air compressor means, it is advisable that theinlet connection of the air duct on the vehicle is fitted with aself-sealing device, or nonreturn valve.

A small wall or small feel may project from the underside of theplatform structure sufficiently to limit the amount of crushing that theflexible elements will receive when a vehicle is at rest.

I claim as my invention:

l. in an air cushion supported materials handling device, asubstantially rigid tubular support framework, said tubular supportframework comprising a plurality of interconnected tubular membersarranged in a horizontal expanse; an impermeable member extending acrosssaid horizontal expanse; means forming an upstanding handle from saidframework for manual propulsion and control of the device, said handlecomprising a tubular member connected to said tubular framework, withits hollow interior in conduit communication with the hollow interiorsof said tubular framework; a plurality of inflatable air pads beneathsaid framework, said pads forming at least partial boundary means for atleast one pressurizable cushion area beneath said framework; and meansfor passing pressurized air through said tubular handle into and throughat least parts of the tubular framework and then separately to saidinflatable pads and said cushion area; said tubular handle includingseparate control valve means for controlling the flow of pressurized airseparately to said inflatable pads and to said cushion area.

1. In an air cushion supported materials handling device, asubstantially rigid tubular support framework, said tubular supportframework comprising a plurality of interconnected tubular membersarranged in a horizontal expanse; an impermeable member extending acrosssaid horizontal expanse; means forming an upstanding handle from saidframework for manual propulsion and control of the device, said handlecomprising a tubular member connected to said tubular framework, withits hollow interior in conduit communication with the hollow interiorsof said tubular framework; a plurality of inflatable air pads beneathsaid framework, said pads forming at least partial boundary means for atleast one pressurizable cushion area beneath said framework; and meansfor passing pressurized air through said tubular handle into and throughat least parts of the tubular framework and then separately to saidinflatable pads and said cushion area; said tubular handle includingseparate control valve means for controlling the flow of pressurized airseparately to said inflatable pads and to said cushion area.